A calibratable tire gauge and system is provided. The present calibratable tire gauge has a first unit nose piece and a second unit nose piece both located at least partially within a main outer enclosure of the gauge. The two piece nose unit of the present calibratable tire gauge may allow the tire gauge to be easily and accurately calibrated in the field. A clicker mechanism located within the tire gauge may allow a user to utilize a, for example, special tool to ‘unlock’ the second unit nose piece with respect to the first unit nose piece and to immobilize the second unit nose piece with respect to an inner wall of the main outer enclosure. Once the first unit nose piece is ‘unlocked’ from the second unit nose piece, a user may twist the scale bar of the gauge to move the first unit nose piece independent from the second unit nose piece. Movement of the first unit nose piece independently with respect to the second unit nose piece therein moves only the first unit nose piece vertically up or down with respect to the bottom of the main outer enclosure of the gauge. As a result, the measured pressure on the scale bar is altered as a result of the ‘read’ line being lowered or raised with respect to the main outer enclosure. The gauge can therefore be easily calibrated in the field.
Calibratable tire gauges are known. For example, U.S. Pat. No. 7,197,919 to Wu discloses a pressure gauge for operative engagement with a gas pressurized system such as a pneumatic tire. It includes a housing having a pressurized gas inlet orifice and a cylindrical bore formed within the housing. A pressure reactive piston is slidably engaged within the cylindrical bore, and a resistance means is disposed within the cylinder to provide a resistive force to the movement of the piston. A calibration rod is disposed proximate the piston, whereby movement of the piston will cause movement of the rod. A pressure indicator bar, which is threadably engaged to the rod, provides an indication of the pressure level of the gas. The calibration rod has a user accessible end, and rotation of the rod causes a calibration adjustment of the pressure indicator bar due to the threaded engagement of the rod with the pressure indicator bar.
Further, U.S. Pat. No. 5,939,627 to Huang discloses a tire pressure gauge having a tubular housing, a pressure measuring head connected to one end of the tubular housing, a pressure responsive piston provided inside the tubular housing and biased by a spring towards a pressure inlet hole of the pressure measuring head, and a plunger actuated by the piston and having a portion that extends out of the other end of the tubular housing. An adjustable extension member, which is disposed between the piston and the plunger, is connected to the plunger to adjust the length of the outwardly extending portion of the plunger or to correct the position of the graduations provided on the plunger relative to a pointing end of the tubular housing where a detected pressure is read. Preferably, the adjustable extension member is a screw member which is threadedly connected to the plunger. Adjustment or correction can be made before or after assembly by turning the screw member relative to the plunger.
Still further, U.S. Pat. No. 4,768,460 to Soon-Fu discloses a pen-like tire gauge having a barrel body shaped as a pen, a guide cylinder secured in the barrel body, a plunger slidingly moving in the cylinder and carrying a semi-cylindrical scale having graduations marked thereon to dispose around the guide cylinder and resiliently tensioned by a restoring spring inserted in a bore of the barrel body, and an air adapter adapted to connect a tire inflating valve for measuring air pressure in the tire when the air is directed into the cylinder to force the plunger and to move the scale for its pressure reading and measurement through a transparent window formed on the body.
However, these patents fail to describe a calibratable tire gauge which is easy to use. Further, these patents fail to provide for a calibratable tire gauge which allows for easy calibration in the field.